The invention relates to an endoscope with electric image transmission which consists of a head with an installed camera, a mobile tube section comprising a pivotal section and a passively flexible section, a control apparatus, and an image display device, and which is particularly suited for medical purposes.
An endoscope having electric image transmission must satisfy special requirements, particularly where it is to function for medical purposes. Above all, the head, which contains a miniaturized television camera, must be capable of being conveyed, by means of a suitable remote control, to the examination location which is usually accessible with difficulty, and said head must be pivotally adjustable to different selected orientations while at the examination location without injuring the patient. In addition, the dissipated heat, which the television camera unavoidably generates in the head, must be carried off such that excessively high temperatures do not result anywhere on the surface of the parts of the apparatus located in the patient.
In the construction of a television endoscope for e.g. stomach-intestinal-examinations, the following difficulties must be overcome:
In the head of the endoscope, a power loss of up to approximately two watts (2 W) results. However, no location of the surface of the parts of the endoscope which are disposed in the patient may exceed the body temperature by more than five kevins (5 K). In some instances, the limit of 5 K is already too high. In addition, the environment (or surroundings) of the endoscope in the patient must be essentially dry; i.e., the endoscope is not immersed in body fluid which would take up the heat and distribute it to such an extent that the mucous membranes would not be impermissibly heated. In addition, there is the fact that the patient only sometimes, not always, senses pain when he is injured by an endoscope which is too hot. Therefore, he cannot reliably warn the physician.
The head of the endoscope must manifest the shape of a circular cylinder of a maximum of approximately 15 mm diameter and a maximum of 20 mm length, and it must be capable of being slipped (or plugged) onto the tube section, it must be capable of being fully sterilized in liquids and/or gases, and it must be correspondingly sealed.
By way of summary, it is apparent that the heat discharge from the head as well as the mechanical construction of the tube section are problematic in the case of an endoscope with electric image transmission.